The present invention relates to a filter for cleaning a fluid, in particular a gaseous fluid, comprising a filter element arranged in a filter housing and a cyclone preseparator that is arranged upstream of the filter element and by means of which the fluid can be guided into the filter element.
DE 20 2005 009 989 U1 discloses an air filter that is integrated into the intake manifold of an internal combustion engine in order to subject the combustion air to be supplied to the internal combustion engine to a filtration process. The air filter is of a multi-part configuration and comprises a filter element arranged in a filter housing and having a cyclone preseparator as a prefilter arranged upstream thereof. A fine filter is arranged downstream. The cyclone preseparator that has the task to separate the coarse dirt particles contained in the unfiltered air comprises a plurality of parallel arranged tubular flow passages of same diameter. These flow passages open into an ante chamber arranged in front of the filter element in the filter housing. An outlet opening extending outwardly in the radial direction is provided at the ante chamber and by means of the outlet opening the dirt particles that have been separated from the fluid can be removed from the preseparator housing.
The flow passages of identical geometry within the cyclone preseparator are matched to a predetermined nominal throughput. Different throughput parameters require therefore a corresponding adaptation of the cyclone preseparator. A reduction of the diameter of the flow passages in the cyclone preseparator improves the cleaning effect but reduces at the same time the nominal throughput.